Auxotroph

Definition

An auxotroph is a microorganism that requires an external supply of a specific nutrient that the parent organism can synthesize on its own. Auxotrophy typically results from mutations that disrupt metabolic pathways.

5 Must Know Facts For Your Next Test

1. Auxotrophs are used in genetic experiments to study gene function and metabolic pathways.
2. Mutations causing auxotrophy often occur in genes encoding enzymes for biosynthetic pathways.
3. Auxotrophs can be identified through replica plating techniques.
4. Reversion mutations can restore prototrophy, allowing the organism to grow without supplementation.
5. In microbial genetics, auxotrophic mutants are valuable tools for mapping genes and understanding metabolic regulation.

Review Questions

• What is an auxotroph and how does it differ from its parent organism?
• How are auxotrophic mutants useful in genetic experiments?
• What methods can be used to identify auxotrophic mutants?

Related terms

Prototroph: A microorganism that can synthesize all necessary nutrients from minimal growth media.

Replica Plating: A technique used to transfer colonies from one plate to another, helping identify mutant strains.

Reversion Mutation: A genetic change that restores the original phenotype by reversing the effect of a prior mutation.